sb25033102
GCN Circular 39955
Subject
SVOM/sb25033102: SVOM detection of an X-ray transient
Date
2025-03-31T03:40:23Z (2 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Yinuo MA, Chao WU, Donghua ZHAO, Wenjin XIE (NAOC), Hatsune GOTO (CEA, Kanazawa Univ) on behalf of the SVOM mission team.
At 2025-03-31T02:04:18 UTC (Tb) SVOM/ECLAIRs triggered on the X-ray transient labelled sb25033102 (SVOM burst-id sb25033102). The following trigger information was received on the ground with low latency by the SVOM VHF Alert Network.
This transient was only detected by the Count-Rate Trigger (CRT), which produced a sequence of 1 alerts. CRT provided the alert with the best signal-to-noise-ratio (SNR) of 15.10 in the [8-120] keV energy band over a time window of 20.48 seconds starting at Tb.
The localization of the best alert is R.A., Dec 289.235, -18.527 degrees:
RA (J2000) = 19h16m56.51s
Dec (J2000) = -18d31m37.10s
with a 90% C.L. radius of 5.48 arcmin (including systematic error of 2 arcmin added in quadrature).
We notice that this transient also triggered SVOM/ECLAIRs at the 1.57 hours before, at 2025-03-31T00:29:51.04 (SVOM/sb25033101). Due to an external ToO was performing by SVOM, no immediate slew was performed on this transient.
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe.
The Burst Advocate (BA) on shift for this burst is Yinuo MA: mayn@bao.ac.cn
Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst.
GCN Circular 39965
Subject
SVOM/sb25033102 is a false trigger
Date
2025-03-31T07:00:53Z (2 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Yinuo MA, Chao WU, Donghua ZHAO, Wenjin XIE (NAOC), Hatsune GOTO (CEA, Kanazawa Univ) on behalf of the SVOM mission team.
The SVOM trigger sb25033102 (GCN Circular 39955) on 2025-03-31T02:04:18 UTC (Tb) is a false trigger, caused by the nearby known bright source SCO X-1, and does not correspond to a real transient.
We apologize for any confusion and inconvenience caused by this mistake.
The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe.